Locomotive boiler feed water heating system and apparatus



Oct. 12, 1937.

J. S. COFFI/N, JR

LOCOMOTIVE BolLER FEED WATER HEATING SYSTEM AND APPARATUS Filed April26, 1934l 5 Sheets-Sheet 1 Oct. 12, 1937( J. s. cow-1N,y JR 2,095,238

LOCOMOTIVE BOILER FEED WATER HEATING SYSTEM AND APPARATUS Filed April26, 1934 5 sheets-sheet 2 J. s. coFFlN, JR 2,095,238

LOCOMOTIVE BOILER FEED WATER HEATING SYSTEM AND APPARAT'YS 5Sheets-Sheet 3 Filed April 26, ,1934

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Patented Oct.l 12, 1937 PATENT {oFElCE LoooMoTIvE EOILEE EEED WATERHEAT- ING SYSTEM AND APPARATUS Joel S.- Cofn, Jr., Englewood, N. J.,assignor to C-S Engineering Company, Englewood, N. J., a corporation ofDelaware Y i Application April 26,

19 Claims.

Thisinvention relates'tothe heating lof boiler feed water, particularlyfor locomotives, and especially tothe heating of a supply of water inthe tender of the locomotive, from which hot water can be VWithdrawn bythe locomotive feed water pump and forced into the boiler. Y

One of the objects of the present invention is toprovide `a fed waterheating apparatus whereinV asupply of hot water is maintained inreadiness to be drawn through the pump and forced into the boilerwhenever the pumpy ation. Y A

In accordance with the present invention the tender of the locomotive isprovided with water `compartments in which the water is heated and fromwhich water is drawn and forced into the boiler. In a locomotive boilerwater heating system it is desirable to maintain a supply of hot waterat the inlet of the feedrwater pump. This ihas been diiiicult toaccomplish in prior tender water heating systems and at the same timemaintain a reliable water supply. If the water withdrawal outlet, orpump inlet, is located at the bottom of a compartment the water abovethe l immediately above the inlet is caused to be heated,

. and also wherein the supply of water to th-e pump inlet is maintainedirrespective of the water'level in the heating compartments, until thetender runs dry. Y Y

A further object is the provision of a plurality of water heatingcompartments connected in series, the compartment directly connected tothe pump inlet being small so that its entire contents are rapidlyheated to supply hotV water to .the boiler instantly the feed water pumpis started in operation. g

An important purpose of the present invention is to supply hot water atsuch a head above theV boiler feed water pump and at such a temperaturethat the pump can handle the hot water at full capacity. There is alwayssome suction at the pump inlet and if the water temperature were closeto the boiling point in the tank the Water i would boil in the pumpinlet,'due to the reduced. Ipressure thereat, so that the pump wouldnotV is started in oper- Y* 1934, Serial No. 722,498

handle ,tl'iewater at full capacity. Furthermore, the pumplmay forcehighly heated Water satisfactorily when the head above the pump is at asuitably vhigh level and may nothandle the same temperature watersatisfactorily when the level is lower. Hence one of the primary objectsof thisinvention is to provide means to maintain a' constant high levelof water above the pump inlet Vand at the same time to keep thetemperature of Vthe'hot water at aV high value but below the boilingpoint.

VA further object of the invention is the provision of a boiler feedwater heating system wherein a heating compartment for theboiler feedwater is provided in'which the water level is maintained constantregardless of the operation of the boiler feed water pump and ofthelevel of water in the main waterrspace of the tender by a water forcingmeans as an injector drawing water from the main water space and forcingit into the heating compartment when the water level falls therein bythe action of the boiler feed water pump, which is located below theWater level in the compartment, and also thermal means responsive to thetemperature of the water in the compartment is provided to maintain thewater at some value below the boiling point, so that the feed water pumpcan always handle the hot water satisfactorily. i

A further object of the invention is the provision o f a plurality ofwater heating compartments in the tender, the compartmentsl being incommunication at the tops and each having heating means therein andvsoarranged that as water is drawn from one compartment hot water fromthe top of the compartment is caused to flow into therst compartment,thereby insuring a progressive ilow of hot Water to the boiler. A waterforcing means is provided to keep the compartments full from water drawnfrom the main water space of the tender. The outlet of therst'compartment, which discharges to thevpump, is located at the bottomof the compartment, and a further objectof theinvention is the provisionof valves 1'0- cated at the bottoms of the compartments and opening fromone into the other and into the main water space of the tenderV so thatupon failure to force water intoV the heating compartments, whichresults in Vanundue depression of the water level in the compartmentsbelow the water level in the main water space, the water will flow underthe head of the water in the main water space into the suction inlet,thereby insuring a supply of water to the pump as long as there isVVwater in the tender.

It is a further object of the invention to have the water capacity ofthe two heating compartments, so related to the Water capacity of thelocomotive boiler between its permitted high and low water levels thatif the pump is started when the water level in the boiler is at the lowwater level line there will be no appreciable amount of cold waterforced into the boiler when the high water level mark is reached.

A further object of the invention is to heat the water in the heatingcompartments by the locomotive engine exhaust steam and. to providevalves responsive to temperatures in the two compartments to control theflow of steam to maintain a constant temperature of the water in thecompartments.

A yet further object is generally to improve upon locomotive feed waterheating systems and methods.

Fig. 1 is a side elevation of a locomotive and tender embodying thepresent invention.

Fig. 2 is a plan view of the locomotive tender and the feed waterheating system therein.

Fig. 3 is a diagrammatic perspective view of the heating system of thetender.

Fig. 4 is a sectional elevation of one of the heating steam controlvalves.

Fig. 5 is a sectional elevation of a temperature responsive pilot valvefor controlling the operation of the valve of Fig. 4.

Fig. 6 is a sectional detail of a water heater in the forward heatingcompartment.

Fig. '7 is a sectional detail of the Water heater of the rearcompartment. v

Fig. 8 is a sectional detail of the float valve that controls theoperation of the water inlector.

Fig. 9 is a detail of a check valve.

Fig. 10 is a diagrammatic plan view of the Y. tender.

bottom of the tender through a pipe I8 and check valve 20. The turbine22 of the pump is supplied by steam through a pipe Z4 and control' valve26 from the turret 28. The tender is of the type having its coal pocketI5 located between two legs I'! and I9 of the water space ZI, and

ie heating compartments of the present invention are convenientlylocated in one of the water legs I S of the tender. The water leg of thetender has the bottom wall 3E), front Wall 32, outer and inner sidewalls 34 and 36, respectively, and the top wall 38. In tenders where thetwo water legs are joined by a water space underneath the coal pocketthe water leg in which the present invention is applied is separatedfrom the water space underneath the tender by a vertical partition wall,which wall as here shown, see especially Fig. 3, is the wall 35 extendeddown to the bottom wall 36. A vertical plate 46 extends transverselyacross the water leg `between the side plates 34 and 36 and is in watertight connection therewith and forms a forward Water heating and storagecompartment 42. A rear water storage and heating compartment 44 isprovided by a second plate 46 which extends across the walter leg and isin water tight connection with the walls thereof. The spacing betweenthe plates 46 and 46 is materially greater than the spacing between theplate 40 and the front wall 32 so that the Water capacity of the rearcompartment 44 is materially greater than that of the front compartment42. The wall 46 of the rear compartment extends up to and joins the topWall 33 of the water leg while the partition wall 46 is terminated asubstantial distance below the top plate 3d so that the two compartmentsare in water communication at the top. This is an important feature ofthe invention. The plate 46 preferably has its rear face lagged withsuitable heat insulating material 48, herein shown as wood boards, toprevent the cooling olf of the hot water in the compartment 44 by thecold water in the tender. The water leg has a rearmost partition wall 50extending transversely thereacross provided with an opening traversed bya screen 52 which prevents the passage of foreign matter to and throughthe heating compartments and into the boiler. Said partition plates 46and 46 are provided with Water tight doors 54 and 56 respectively whichwhen open permit passage of a workman into the compartments. The screen52 is also carried by a door which can be opened for the same purpose.The water outlet 5B of the compartments is located at the bottom of theforemost or small heating and storage compartment 42, the outlet waterflowing through a valve 6G and a flexible hose bag G2 to the suctionpipe 64 of the feed water pump I6. Check valves are located at thebottom of the partition plate 4i! and open to admit the passage of waterfrom the large rear compartment 44 into the small forward compartment 42when the water level in the small compartment reaches an abnormally lowpoint or below the level of the top of the partition wall 4S. Thepartition wall G6 of the rear compartment is similarly provided with aseries of similar check valves 68 to allow water to flow into the rearcompartment from the main Water space of the tender when the water levelin the rear compartment becomes lower than the water level in the mainwater space of the tender. These valves assure a supply of water to theinlet of the pumpfor so long as there is water in the tender and in theevent of a failure of the Water forcing means for the heatingcompartments, presently to be described, to operate.

Water from the main water storage space of the tender is forced by awater injector 'I6 into the bottom of the rear compartment 44 during thetime that water is withdrawn from the cornpartments. Said injector islocated at the rear of the partition wall 46 and between it and thescreen wall 5i? and discharges water through the middle one of the checkvalves 68 into the bottom of the rear compartment 44. The injector isoperated by pressure water from the pump I6 supplied through a pipe 'I2leading to a float valve 'I4 which receives water through a pipe I6connected to the high pressure outlet pipe I8 of the pump. The floatvalve, see especially Figs. l and 8, is located in the upper part of theforward water heating compartment 42 and is adapted to be opened whenthe water level drops in the compartment and closed when the water levelrises, thereby to maintain a constant level of water in the two heatingcompartments. The oat valve may be of any suitable construction but asherein illustrated comprises a shell i8 that has internal confrontingbosses 86 that are journalled are provided with side ports Y82 that canmove into andv out of register with cooperating ports 84 of the bosses88 so as tofcontrol thev passage of waterf through the shell 18 betweenthe two pipes,

depending upon the position ci` the shell. The shell18 is fixed to andcarries a oat member 82 that is partially submerged in the water of thetwo heating compartments 42 and 44. 'I'he ends 12a and 'iia of the pipes12 and 16 are disposed below a Vcover 88, see especially Figs. 2 and 3,

resting on the top wall 38 of the water heating compartment so that thefloat mechanism when disconnected from the pipes 12 and 16 can bewithdrawn from the compartments. As thus arranged when the pump i6 isstarted in operation to withdraw water from the heating compartmentsVand the water level therein descends the pressure water supplied atV thepump outlet automatically actuates the injector 18 toY force water fromthe main water space of the tender to the heating compartments. Thecapacity of the injector 18 is adapted to be at least equal to thecapacity of the pump, so that the injector can maintain a constant leveloi" water in the heating compartments irrespective of the level of waterin the main water space of the tender.

The water that actuates the injector is .heated and the heat is utilizedin the injector for heating the injected water so that there is verylittle Y loss of heat since the thermal eiciency of the injector isalmost perfect.

,Steam for heating the water in the heating compartments is taken fromthe exhaust steam chest of the locomotive cylinders l2 and is conductedrearwardly toward the tender through pipes 98 and non-return checkvalves 92, but one pipe and valvelbeing shown, to the rear of thelocomotive wherein the steam passes through a pair of flexible hose bags84 and 96 into two pipes 98 and |88. Said pipes pass through the frontwall SZotthe'tender and Vinto .the water space and thence upwardlythrough the. forward heating compartment 42 and through the top wall 38and into a pair of steam control valves |82 and |84, the Vpipes 88 `and|88 being connected by a pipe |86, see Figs. 2 and 3, toequalize steamiiow andV pressure in the two hose bags 94 and 86. The outlet or thevalve |82 is connected through a pipe |88 that passes downwardly throughthe top wall 38 and into the forward heating compartment 42 where itcommunicates with a heater I I0. Said heater is located in aboutthevertical middle of the forward compartment and'comprises essentially ahorizontal cylindrical conduit H2, see especially Fig. 6, the ends ofwhich are Vclosed removably by caps ||4 andhaving small orices I6 in thebottom thereof through which small jets of steam can pass into thesurrounding water thereby to heat the water. Theoutlet of the valve |84is connected to a pipe H3 Ywhich'extends downwardly .through the topwall 38 and is provided with `two branches |28 that are connected withvheaters |22, Vshown in detail in Figyl, which heaters are or may beidentical and are preferably of the circulating injecting type. Eachheater" comprises a discoidal casing having vertically spaced upper andlow-er walls |24 and |28 providing between them an annular outletV |28.A partition wall or diaphragm |38 is Y located betweenthe two walls andprovides between them an upper steam chamber |32 and a lower waterchamber |343.Y The steam branch Y| 28 is in communication with the steamchamber |32 Yand the outlet ofthe injector 18.

and a suction pipe |36 is connected with the l water chamber |34 anddepends below the casing into the annular opening Y|28 so that byinjector` action it induces a flow-of water up the suction pipe and intothe passage |28 where the steam commingles with the water and iscondensed and the waterV creates a strong circulation of the water inthe rear compartment. The flow of heating steam through the heaters iscontrolled'by the aforesaid valves 682, |84, as determined by thetemperature of the water in the heating compartments. In someVapplication of my invention I may prefer to omit valve |84, and alsovalve |82, or to substitute therefor a manuallyoperated valve or valvesi635 as shown in Fig, 12 and to permit the exhaust steam when availableto flow continuously into compartment 44 from pipe |86. IThe valves |82and |84 are or can be identical and one is illustrated in cross sectionin Fig. e, the Valve comprising a casing |42 having an inlet |44 whichreceives steam from a pipe 98 and an outlet 548 which discharges steaminto a heater pipe H8. A partition'wall or diaphragm |48 is locatedbetween the inlet and outlet of the valve and is provided with a valveseat |58 and a valve member 952 cooperating with said seat. The stem |54of the valve member carries a piston |55 which is materially greater indiameter than the diameter of the valve |52. The piston is reciprocablein a cylinder sleeve |58 carried by the cas- Y ing |42 and open to thesteam inlet passage |24V andV closed at the other endrby a cover |38 sodisposed that there is a steam space |62 between the cover and theunderside of the piston |56. The steam space is provided with an outlet|64 in the cover. The vpiston is provided with a leakage passage betweenthe steam inlet |44 and the |32, the leakage passage being herein shownin exaggerated form as a peripheral clearance space |63 between' theperiphery ofthe piston and the cylinder |58. A spring |68 bears againstthe piston tending when pressure conditions permit to raise the valve|52 oi its seat. The outlet passage H34 of the steam space |62 isgreater in area than the leakage passage |661l from Y the steam inletinto said steam space. 'Ihus when the passage |54 is completely open toatmosphere the total pressure of steam is greater on the piston i56 thanon the underside of the valve |52 and hence' eiects the closing of thevalve and maintaining the valve closed. When, however, the outletpassage |63 is closed the steam pressure builds up in the steam space|64 through the leakage passage |68 to equalize pressure on oppositesides of the piston and hence the valve opens. The flow oi steam throughthe outlets Ifl of the two valves E02, |84 is controlled by the valves|18, |12, each valve controlling a separate steam valve and beingoperated in accordance with the temperature of aseparate heatingcompartment. The valve |18 is influenced by the temperature in theforward heating compartment 42 and controls rthe valve |82 that suppliesheating steam to said compartment. The

supplies steam to said compartment. The Valves is heated. This type ofinjectorV `the associated steam control valve.

|10 and |12 are or can be identical and one is illustrated in Fig. 5.These valves are of a common type having a bellows or diaphragm eX-panded and contracted by changes in temperature of the water in theassociated compartment,

as shown in Fig. 5, the valve comprising a casing having an inlet |13and an outlet |161 and valve discs |15 interposed between the inlet andoutlet and carried by a stem iilxed to one end of an expansble diaphragmi3d. The arrangement is such that as the diaphragm or bellows expandsdownwardly the valve is opened and as the diaphragm is contracted thevalve closes. The interior of the diaphragm of the valve |10 isconnected through a exible or other tube |82 with a bulb |84 locatedwithin the forward heating compartment d2. The bellows of the valve |12.is connected through a similar tube |86 with a bulb |83 located in therear compartment e4. The arrangement is such that as the fluid withinthe bulb expands the associated diaphragm is caused to expand andoperate the valve. The inlets |13 of the valves are connected throughpipes and |92, respectively, with the leakage outlets !El of the steamregulating valves lili! and led, and the arrangement is such that whenthe temperature of the water in a compartment rises to a suitable degreethe temperature responsive valve is caused to open and effect theclosing of The control is also such that the degree of opening or" thesteam valves is controlled so as to tend to maintain a constanttemperature of water in the heating compartments. With this arrangementwhen `the temperature of `water in any compartment drops the associatedsteam valve is opened to effect the heating of the water in thecompartment. The arrangement is also such that the high temperature ofthe water is limited to a Value such that, at the height of water in thecompartments above the pump inlet, the pump can handle the hotwater'satisactorily.

The two compartments are provided with a vent pipe |98. The valves iiland IEM are located a substantial distance above the water level in theheating compartments and the outlet pipes |98 and |98 are provided withvacuum breaking Valves 99S which admit air into the steam piping in theevent of the formation of a vacuum therein so as to prevent water frombeing drawn into the steam piping from the heating compartments.

The operation of the system is essentially as follows:

When the locomotive is moving and is using steam the water` in the twoheating compartments 42 and d is maintained at the desired elevatedtemperature below the boiling point by the automatic action of thetemperature control steam valves |82 and lli. Thus when the pump it isset in operation to force water into the boiler hot water is immediatelydrawn into the pump. The lowering of the water level in the compartmentsdue to the action of the pump causes the lowering of the oat 86 whichopens the associated valve to admit high pressure water from the pumpinto the nozzle of the injector 1i), thereby to force water from themain water space of the tender into the compartments. The float thusacts to Ymaintain the water level in the compartments substantiallyconstant irrespective of the water level in the main water space of thetender. The water passed into the injector from the pump is hot and sowarms the incoming water. The incoming water is heated and the hot waterflows upwardly in that compartment and over the top of the partitionwall 40 into the forward compartment 42 so that the pump, whenoperating, is always supplied with hot water. When the temperature ofthe water in the compartments becomes reduced to a predetermined extentthe steam valves |018 and |02 open to reheat the water. The capacity ofthe steam supply means is suicient to heat the water ed to the boiler tothe desired elevated temperature when the locomotive and pump areoperating continuously for long periods. Under such conditions the Waterin compartment 44 becomes heated to a certain extent and that incompartment i2 is further heated to the desired temperature for boilerfeeding.

Under conditions of totally intermittent operation such as may obtain inthe case of a switching engine in which the boiler may be filled whilethe engine is standing and no steam is available for water heating, andin which full power may subsequently be exercised in hauling a trainwhile no water is fed, my invention will be seen to be particularlyadapted to eiiect the required feed water heating. Under such conditionsI may proportion the capacity of the two compartments i2 and lili, sothat their total capacity is approximately equal to the water capacityof the boiler between the permissible high and low gauge glass levels.'When the engine is working and pulling the boiler level down from thehigh to the low gauge glass, the corresponding volume of water is beingheated in the two compartments to the required temperature. First theforward or smaller con'ipartment is heated to the required temperatureand urther heating therein becomes prevented by the operation of thethermostat. Subsequently the larger rear compartment becomes heated tothe required temperature. The locomotive may then cease Working and thepump may fill the boiler with heated water, leaving substantially coldwater in the compartments, and the operation may be repeated.

Actually the operation of a particular locomotive is usuallyintermediate between continuous and intermittent operation and it willbe seen that by the adoption of a small iront compartment I am able toheat this to the thermostat shut-oir" temperature rapidly. If, in theabove described intermittent operation, the pump is started before thecomplete body of water in both compartments has become heated, it willinitially, at least, draw completely heated water from the irontcompartment. It will be seen that by properly proportioning the sizes ofthe compartments G2 and Gd, I may secure the best operation for aparticular locomotive service.

The check valves 66 insure a supply of water to the pump in the event offailure of the injector 1Q to operate and thus assure a water supply forthe boiler as long as there is water in the tender.

I claim:

l. Boiler feed water heating apparatus cornprising two heatingcompartments connected at the top, a heater in each compartment, a wateroutlet at the bottom of one compartment and a water inlet at the bottomof the other compartment.

2. Boiler feed water heating apparatus comprisine two heatingcompartments connected at the top, a heater in each compartment, a wateroutlet at the bottom of one compartment and a water inlet in the othercompartment, the compartment associated with the water outlet beingrelatively small and the otherucompartment thtop, a heater in eachcompartment, a water outlet at'the bottom of one compartment and aVwater inlet at the bottom of the other compartment, andmeans formaintaining a normal water level in said ,compartments abo-ve the bottomof the interconnection therebetween.

y2l. Boiler'feed lwater heating apparatus com-- outletat the bottom ofone compartment anda `water inlet at the bo-ttom of theothercompartment, a boiler feed water pump connected with said outlet, waterforcing means Ydischarging through said inlet, ra'main water Vspacesupplying water to said forcing means, and means for maintaining aconstant water level in-said com- Ypfart'ments irrespective'of the waterlevel in said main water space.

l5. A boiler feed water heating apparatus cornprising two compartmentshaving an interconnection therebetweenat the top, a water outlet at thebottom of one compartment anda Water inlet atY the bottom of the othercompartment, a heater in each compartment, means for forcing water intosaid inlet, and means responsive to the level of water in onecompartment for operatingsaidforcing means to maintain a normal waterlevel above the interconnection between said compartments. Y A 1 6. Aboiler feed water heating system comprising two water heatingcompartments connected at the top, a heater in each compartment, aboiler feedwater pump having a suction pipe opening into the bottom'ofone of said compart-V ments, means for forcing water into the bottom ofsaid Vother compartment, said means being operated by the waterpressure'of said feed water pump, and means responsive to the waterlevel in said one compartment for controlling the operation of saidforcing means for maintaining a normal water level above the bottomY ofthe connection between said compartments. Y

'7. A boiler feed Water heating apparatus comprising two water heatingcompartments having a vertical separating partition that terminatesbelow the tops of said compartments so that said compartments are incommunication above the top of said partition, a heater in eachcompartment, and means to effect a flow of water intoV the bottom of onecompartment and upwardly therein and over the top of said partition anddownwardly Within and out of the bottom of said other compartment.

8. vA boiler feed water heating apparatus comprising two water heatingcompartments having a vertical separating partition that terminatesbelow thetops of said compartments so that said compartments are incommunication above the top of said partition, a heater in eachcompartment, a boiler feed water pump having a suctionV pipe openinginto the bottom of one compartment, Water forcing means opening into thebottom of saidV other compartment, and constant level mechanismcontrolling the operation of said forcing means and governed by thewater level in said one compartment.

9. A boiler feed water heating apparatus comprising two water heatingcompartments having a vertical separating partition that terminatesbelow the tops of said compartments so that said compartments are incommunication above the top of said partition, a heater in eachcompartment, a boiler feed water pump having a suction pipe opening intothe bottom of one compartment, water forcing means opening into Ythebottom of said other compartment, and constant level mechanismcontrolling the operation of said forcing means and governed by thewater level in said one compartment and operative to maintain a normalwater level Vabovethe top of said partition. Y Y

10. A boiler feed water heating apparatus comprising two water heatingcompartments'having ,a vertical separatingV partition that terminatesbelow the tops of'said compartments so that said 'compartments are incommunication above theV top` ofsaid partition, a heater in eachcompartment, a boiler feed water pump having a suction pipe opening intothe bottom of one compartment, water forcing means opening intothebottom of said other compartment, and constant level mechanismcontrolling the operation of said forcing means and governed by thewater level in said one compartment, said forcing means having means bywhich it is operatedby the high pressure water of said boilerrfeed waterpump.

11. A boiler feed water heating system compris-Y ing a main watercompartment, a heating compartment in which the water level is normallymaintained higher than and independent of the water level in said maincompartment, a heater for heating the water that is in said heatingcompartment, a boiler Vfeed water pump receiving water from said heatingcompartment and having a suction pipe opening thereinto, meansrespontain a normal water level in said heatingcompartment, Iand meansoperative upon the failure of said forcing means to maintain a normalwater level to admit cold water from said main Y compartment into saidsuction pipe without being heated by said water.

12. Boiler feed water heating apparatus com-- other compartment, andmeans operative upon Y an abnormal depression of said water level belowthe connection between said compartments to establish communicationbetween said compartments at the bottom thereof and also between saidcompartments and said main water` storage space.

14. Boiler feed Water heating apparatus comprising a main water space,two Water heating compartments connected at the top, a heater in eachcompartment, a boiler feed water pump having a suction pipe opening intothe bottom of one compartment, water forcing means for forcing waterfrom said main water space into said other compartment, and check valvesl0- cated at the bottom of said compartments for admitting water fromsaid main water space through said compartments into the inlet of saidsuction pipe when the water level in said compartments becomesabnormally low.

15. A boiler feed water heating system comprising two water heatingtanks of unequal capacity interconnected at the top, a feed water pumpdrawing water from the bottom of one compartment, means for admittingwater into the bottom of the other compartment, a heater in eachcompartment, and temperature responsive means separately associated witheach compartment and influenced by the water temperature therein forcontrolling the operation of the heater in the associated compartment.

16. Boiler feed water heating apparatus comprising a large and a smallwater heating compartment communicating at the top, a steam heater ineach Compartment, a boiler feed water pump withdrawing water from saidsmall compartment, thermo-responsive means governed by the temperatureof the water in said small compartment for controlling the supply ofsteam to the heater in said small compartment, and means for passingsteam in a continuous manner whenever heating steam is available to theheater in said large compartment.

17. A locomotive boiler feed water heating system comprising a mainwater compartment, water heating and storage means having means wherebythe hottest water is in one part and the coolest water is in anotherpart of said storage means, a boiler feed water pump drawing water fromthe hottest water part of the storage means, forcing means forcing waterfrom said main water compartment into the coolest water part of saidstorage means and having means associated with it operative to maintainin said storage means a constant water level that is higher than in saidmain compartment, and. heating means in said storage means.

18. Locomotive boiler feed water heating apparatus comprising a coldwater space, a heating compartment, a boiler feed water pump drawingwater from said compartment, means for introducing water from said coldwater space into said compartment at such a rate during each` pumpdrawing hot water from the hot water part of said compartment, means forintroducing water from said `cold Water space into the cold water partof said compartment at such a rate during each operation of said pump asto keep the water level substantially constant in said compartment atsuch time, and means for heating the water after introduction to saidcompartment between pump operations.

JOEL S. COFFIN, JR.

